Problem: Simplify the following expression: $y = \dfrac{9}{7r} - \dfrac{-5}{7r}$
Explanation: Since the expressions have the same denominator we simply combine the numerators: $y = \dfrac{9 - (-5)}{7r}$ Combine like terms: $y = \dfrac{14}{7r}$ Simplify by dividing numerator and denominator by 7: $y = \dfrac{2}{r}$